Lines Matching defs:*
2 * PCM Interface - mmap
3 * Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
5 * This library is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License as
7 * published by the Free Software Foundation; either version 2.1 of
8 * the License, or (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #include <stdio.h>
22 #include <malloc.h>
23 #include <string.h>
24 #include <sys/poll.h>
25 #include <sys/mman.h>
26 #include <sys/shm.h>
27 #include "pcm_local.h"
29 size_t page_size(void)
31 long s = sysconf(_SC_PAGE_SIZE);
32 assert(s > 0);
33 return s;
36 size_t page_align(size_t size)
38 size_t r;
39 long psz = page_size();
40 r = size % psz;
41 if (r)
42 return size + psz - r;
43 return size;
46 size_t page_ptr(size_t object_offset, size_t object_size, size_t *offset, size_t *mmap_offset)
48 size_t r;
49 long psz = page_size();
50 assert(offset);
51 assert(mmap_offset);
52 *mmap_offset = object_offset;
53 object_offset %= psz;
54 *mmap_offset -= object_offset;
55 object_size += object_offset;
56 r = object_size % psz;
57 if (r)
58 r = object_size + psz - r;
59 else
60 r = object_size;
61 *offset = object_offset;
62 return r;
65 void snd_pcm_mmap_appl_backward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
67 snd_pcm_sframes_t appl_ptr = *pcm->appl.ptr;
68 appl_ptr -= frames;
69 if (appl_ptr < 0)
70 appl_ptr += pcm->boundary;
71 *pcm->appl.ptr = appl_ptr;
74 void snd_pcm_mmap_appl_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
76 snd_pcm_uframes_t appl_ptr = *pcm->appl.ptr;
77 appl_ptr += frames;
78 if (appl_ptr >= pcm->boundary)
79 appl_ptr -= pcm->boundary;
80 *pcm->appl.ptr = appl_ptr;
83 void snd_pcm_mmap_hw_backward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
85 snd_pcm_sframes_t hw_ptr = *pcm->hw.ptr;
86 hw_ptr -= frames;
87 if (hw_ptr < 0)
88 hw_ptr += pcm->boundary;
89 *pcm->hw.ptr = hw_ptr;
92 void snd_pcm_mmap_hw_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
94 snd_pcm_uframes_t hw_ptr = *pcm->hw.ptr;
95 hw_ptr += frames;
96 if (hw_ptr >= pcm->boundary)
97 hw_ptr -= pcm->boundary;
98 *pcm->hw.ptr = hw_ptr;
101 static snd_pcm_sframes_t snd_pcm_mmap_write_areas(snd_pcm_t *pcm,
102 const snd_pcm_channel_area_t *areas,
103 snd_pcm_uframes_t offset,
104 snd_pcm_uframes_t size)
106 snd_pcm_uframes_t xfer = 0;
108 if (snd_pcm_mmap_playback_avail(pcm) < size) {
109 SNDMSG("too short avail %ld to size %ld", snd_pcm_mmap_playback_avail(pcm), size);
110 return -EPIPE;
112 while (size > 0) {
113 const snd_pcm_channel_area_t *pcm_areas;
114 snd_pcm_uframes_t pcm_offset;
115 snd_pcm_uframes_t frames = size;
116 snd_pcm_sframes_t result;
118 snd_pcm_mmap_begin(pcm, &pcm_areas, &pcm_offset, &frames);
119 snd_pcm_areas_copy(pcm_areas, pcm_offset,
120 areas, offset,
121 pcm->channels,
122 frames, pcm->format);
123 result = snd_pcm_mmap_commit(pcm, pcm_offset, frames);
124 if (result < 0)
125 return xfer > 0 ? (snd_pcm_sframes_t)xfer : result;
126 offset += result;
127 xfer += result;
128 size -= result;
130 return (snd_pcm_sframes_t)xfer;
133 static snd_pcm_sframes_t snd_pcm_mmap_read_areas(snd_pcm_t *pcm,
134 const snd_pcm_channel_area_t *areas,
135 snd_pcm_uframes_t offset,
136 snd_pcm_uframes_t size)
138 snd_pcm_uframes_t xfer = 0;
140 if (snd_pcm_mmap_capture_avail(pcm) < size) {
141 SNDMSG("too short avail %ld to size %ld", snd_pcm_mmap_capture_avail(pcm), size);
142 return -EPIPE;
144 while (size > 0) {
145 const snd_pcm_channel_area_t *pcm_areas;
146 snd_pcm_uframes_t pcm_offset;
147 snd_pcm_uframes_t frames = size;
148 snd_pcm_sframes_t result;
150 snd_pcm_mmap_begin(pcm, &pcm_areas, &pcm_offset, &frames);
151 snd_pcm_areas_copy(areas, offset,
152 pcm_areas, pcm_offset,
153 pcm->channels,
154 frames, pcm->format);
155 result = snd_pcm_mmap_commit(pcm, pcm_offset, frames);
156 if (result < 0)
157 return xfer > 0 ? (snd_pcm_sframes_t)xfer : result;
158 offset += result;
159 xfer += result;
160 size -= result;
162 return (snd_pcm_sframes_t)xfer;
166 * \brief Write interleaved frames to a PCM using direct buffer (mmap)
167 * \param pcm PCM handle
168 * \param buffer frames containing buffer
169 * \param size frames to be written
170 * \return a positive number of frames actually written otherwise a
171 * negative error code
172 * \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED or #SND_PCM_STATE_RUNNING)
173 * \retval -EPIPE an underrun occurred
174 * \retval -ESTRPIPE a suspend event occurred (stream is suspended and waiting for an application recovery)
176 * If the blocking behaviour is selected, then routine waits until
177 * all requested bytes are played or put to the playback ring buffer.
178 * The count of bytes can be less only if a signal or underrun occurred.
180 * If the non-blocking behaviour is selected, then routine doesn't wait at all.
182 snd_pcm_sframes_t snd_pcm_mmap_writei(snd_pcm_t *pcm, const void *buffer, snd_pcm_uframes_t size)
184 snd_pcm_channel_area_t areas[pcm->channels];
185 snd_pcm_areas_from_buf(pcm, areas, (void*)buffer);
186 return snd_pcm_write_areas(pcm, areas, 0, size,
187 snd_pcm_mmap_write_areas);
191 * \brief Write non interleaved frames to a PCM using direct buffer (mmap)
192 * \param pcm PCM handle
193 * \param bufs frames containing buffers (one for each channel)
194 * \param size frames to be written
195 * \return a positive number of frames actually written otherwise a
196 * negative error code
197 * \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED or #SND_PCM_STATE_RUNNING)
198 * \retval -EPIPE an underrun occurred
199 * \retval -ESTRPIPE a suspend event occurred (stream is suspended and waiting for an application recovery)
201 * If the blocking behaviour is selected, then routine waits until
202 * all requested bytes are played or put to the playback ring buffer.
203 * The count of bytes can be less only if a signal or underrun occurred.
205 * If the non-blocking behaviour is selected, then routine doesn't wait at all.
207 snd_pcm_sframes_t snd_pcm_mmap_writen(snd_pcm_t *pcm, void **bufs, snd_pcm_uframes_t size)
209 snd_pcm_channel_area_t areas[pcm->channels];
210 snd_pcm_areas_from_bufs(pcm, areas, bufs);
211 return snd_pcm_write_areas(pcm, areas, 0, size,
212 snd_pcm_mmap_write_areas);
216 * \brief Read interleaved frames from a PCM using direct buffer (mmap)
217 * \param pcm PCM handle
218 * \param buffer frames containing buffer
219 * \param size frames to be written
220 * \return a positive number of frames actually read otherwise a
221 * negative error code
222 * \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED or #SND_PCM_STATE_RUNNING)
223 * \retval -EPIPE an overrun occurred
224 * \retval -ESTRPIPE a suspend event occurred (stream is suspended and waiting for an application recovery)
226 * If the blocking behaviour was selected, then routine waits until
227 * all requested bytes are filled. The count of bytes can be less only
228 * if a signal or underrun occurred.
230 * If the non-blocking behaviour is selected, then routine doesn't wait at all.
232 snd_pcm_sframes_t snd_pcm_mmap_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t size)
234 snd_pcm_channel_area_t areas[pcm->channels];
235 snd_pcm_areas_from_buf(pcm, areas, buffer);
236 return snd_pcm_read_areas(pcm, areas, 0, size,
237 snd_pcm_mmap_read_areas);
241 * \brief Read non interleaved frames to a PCM using direct buffer (mmap)
242 * \param pcm PCM handle
243 * \param bufs frames containing buffers (one for each channel)
244 * \param size frames to be written
245 * \return a positive number of frames actually read otherwise a
246 * negative error code
247 * \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED or #SND_PCM_STATE_RUNNING)
248 * \retval -EPIPE an overrun occurred
249 * \retval -ESTRPIPE a suspend event occurred (stream is suspended and waiting for an application recovery)
251 * If the blocking behaviour was selected, then routine waits until
252 * all requested bytes are filled. The count of bytes can be less only
253 * if a signal or underrun occurred.
255 * If the non-blocking behaviour is selected, then routine doesn't wait at all.
257 snd_pcm_sframes_t snd_pcm_mmap_readn(snd_pcm_t *pcm, void **bufs, snd_pcm_uframes_t size)
259 snd_pcm_channel_area_t areas[pcm->channels];
260 snd_pcm_areas_from_bufs(pcm, areas, bufs);
261 return snd_pcm_read_areas(pcm, areas, 0, size,
262 snd_pcm_mmap_read_areas);
265 int snd_pcm_channel_info_shm(snd_pcm_t *pcm, snd_pcm_channel_info_t *info, int shmid)
267 switch (pcm->access) {
268 case SND_PCM_ACCESS_MMAP_INTERLEAVED:
269 case SND_PCM_ACCESS_RW_INTERLEAVED:
270 info->first = info->channel * pcm->sample_bits;
271 info->step = pcm->frame_bits;
272 break;
273 case SND_PCM_ACCESS_MMAP_NONINTERLEAVED:
274 case SND_PCM_ACCESS_RW_NONINTERLEAVED:
275 info->first = 0;
276 info->step = pcm->sample_bits;
277 break;
278 default:
279 SNDMSG("invalid access type %d", pcm->access);
280 return -EINVAL;
282 info->addr = 0;
283 if (pcm->hw_flags & SND_PCM_HW_PARAMS_EXPORT_BUFFER) {
284 info->type = SND_PCM_AREA_SHM;
285 info->u.shm.shmid = shmid;
286 info->u.shm.area = NULL;
287 } else
288 info->type = SND_PCM_AREA_LOCAL;
289 return 0;
292 int snd_pcm_mmap(snd_pcm_t *pcm)
294 int err;
295 unsigned int c;
296 assert(pcm);
297 if (CHECK_SANITY(! pcm->setup)) {
298 SNDMSG("PCM not set up");
299 return -EIO;
301 if (CHECK_SANITY(pcm->mmap_channels || pcm->running_areas)) {
302 SNDMSG("Already mmapped");
303 return -EBUSY;
305 err = pcm->ops->mmap(pcm);
306 if (err < 0)
307 return err;
308 if (pcm->mmap_shadow)
309 return 0;
310 pcm->mmap_channels = calloc(pcm->channels, sizeof(pcm->mmap_channels[0]));
311 if (!pcm->mmap_channels)
312 return -ENOMEM;
313 pcm->running_areas = calloc(pcm->channels, sizeof(pcm->running_areas[0]));
314 if (!pcm->running_areas) {
315 free(pcm->mmap_channels);
316 pcm->mmap_channels = NULL;
317 return -ENOMEM;
319 for (c = 0; c < pcm->channels; ++c) {
320 snd_pcm_channel_info_t *i = &pcm->mmap_channels[c];
321 i->channel = c;
322 err = snd_pcm_channel_info(pcm, i);
323 if (err < 0) {
324 free(pcm->mmap_channels);
325 free(pcm->running_areas);
326 pcm->mmap_channels = NULL;
327 pcm->running_areas = NULL;
328 return err;
331 for (c = 0; c < pcm->channels; ++c) {
332 snd_pcm_channel_info_t *i = &pcm->mmap_channels[c];
333 snd_pcm_channel_area_t *a = &pcm->running_areas[c];
334 char *ptr;
335 size_t size;
336 unsigned int c1;
337 if (i->addr) {
338 a->addr = i->addr;
339 a->first = i->first;
340 a->step = i->step;
341 continue;
343 size = i->first + i->step * (pcm->buffer_size - 1) + pcm->sample_bits;
344 for (c1 = c + 1; c1 < pcm->channels; ++c1) {
345 snd_pcm_channel_info_t *i1 = &pcm->mmap_channels[c1];
346 size_t s;
347 if (i1->type != i->type)
348 continue;
349 switch (i1->type) {
350 case SND_PCM_AREA_MMAP:
351 if (i1->u.mmap.fd != i->u.mmap.fd ||
352 i1->u.mmap.offset != i->u.mmap.offset)
353 continue;
354 break;
355 case SND_PCM_AREA_SHM:
356 if (i1->u.shm.shmid != i->u.shm.shmid)
357 continue;
358 break;
359 case SND_PCM_AREA_LOCAL:
360 break;
361 default:
362 assert(0);
364 s = i1->first + i1->step * (pcm->buffer_size - 1) + pcm->sample_bits;
365 if (s > size)
366 size = s;
368 size = (size + 7) / 8;
369 size = page_align(size);
370 switch (i->type) {
371 case SND_PCM_AREA_MMAP:
372 ptr = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_FILE|MAP_SHARED, i->u.mmap.fd, i->u.mmap.offset);
373 if (ptr == MAP_FAILED) {
374 SYSERR("mmap failed");
375 return -errno;
377 i->addr = ptr;
378 break;
379 case SND_PCM_AREA_SHM:
380 if (i->u.shm.shmid < 0) {
381 int id;
382 /* FIXME: safer permission? */
383 id = shmget(IPC_PRIVATE, size, 0666);
384 if (id < 0) {
385 SYSERR("shmget failed");
386 return -errno;
388 i->u.shm.shmid = id;
389 ptr = shmat(i->u.shm.shmid, 0, 0);
390 if (ptr == (void *) -1) {
391 SYSERR("shmat failed");
392 return -errno;
394 /* automatically remove segment if not used */
395 if (shmctl(id, IPC_RMID, NULL) < 0){
396 SYSERR("shmctl mark remove failed");
397 return -errno;
399 i->u.shm.area = snd_shm_area_create(id, ptr);
400 if (i->u.shm.area == NULL) {
401 SYSERR("snd_shm_area_create failed");
402 return -ENOMEM;
404 if (pcm->access == SND_PCM_ACCESS_MMAP_INTERLEAVED ||
405 pcm->access == SND_PCM_ACCESS_RW_INTERLEAVED) {
406 unsigned int c1;
407 for (c1 = c + 1; c1 < pcm->channels; c1++) {
408 snd_pcm_channel_info_t *i1 = &pcm->mmap_channels[c1];
409 if (i1->u.shm.shmid < 0) {
410 i1->u.shm.shmid = id;
411 i1->u.shm.area = snd_shm_area_share(i->u.shm.area);
415 } else {
416 ptr = shmat(i->u.shm.shmid, 0, 0);
417 if (ptr == (void*) -1) {
418 SYSERR("shmat failed");
419 return -errno;
422 i->addr = ptr;
423 break;
424 case SND_PCM_AREA_LOCAL:
425 ptr = malloc(size);
426 if (ptr == NULL) {
427 SYSERR("malloc failed");
428 return -errno;
430 i->addr = ptr;
431 break;
432 default:
433 assert(0);
435 for (c1 = c + 1; c1 < pcm->channels; ++c1) {
436 snd_pcm_channel_info_t *i1 = &pcm->mmap_channels[c1];
437 if (i1->type != i->type)
438 continue;
439 switch (i1->type) {
440 case SND_PCM_AREA_MMAP:
441 if (i1->u.mmap.fd != i->u.mmap.fd ||
442 i1->u.mmap.offset != i->u.mmap.offset)
443 continue;
444 break;
445 case SND_PCM_AREA_SHM:
446 if (i1->u.shm.shmid != i->u.shm.shmid)
447 continue;
448 /* follow thru */
449 case SND_PCM_AREA_LOCAL:
450 if (pcm->access != SND_PCM_ACCESS_MMAP_INTERLEAVED &&
451 pcm->access != SND_PCM_ACCESS_RW_INTERLEAVED)
452 continue;
453 break;
454 default:
455 assert(0);
457 i1->addr = i->addr;
459 a->addr = i->addr;
460 a->first = i->first;
461 a->step = i->step;
463 return 0;
466 int snd_pcm_munmap(snd_pcm_t *pcm)
468 int err;
469 unsigned int c;
470 assert(pcm);
471 if (CHECK_SANITY(! pcm->mmap_channels)) {
472 SNDMSG("Not mmapped");
473 return -ENXIO;
475 if (pcm->mmap_shadow)
476 return pcm->ops->munmap(pcm);
477 for (c = 0; c < pcm->channels; ++c) {
478 snd_pcm_channel_info_t *i = &pcm->mmap_channels[c];
479 unsigned int c1;
480 size_t size = i->first + i->step * (pcm->buffer_size - 1) + pcm->sample_bits;
481 if (!i->addr)
482 continue;
483 for (c1 = c + 1; c1 < pcm->channels; ++c1) {
484 snd_pcm_channel_info_t *i1 = &pcm->mmap_channels[c1];
485 size_t s;
486 if (i1->addr != i->addr)
487 continue;
488 i1->addr = NULL;
489 s = i1->first + i1->step * (pcm->buffer_size - 1) + pcm->sample_bits;
490 if (s > size)
491 size = s;
493 size = (size + 7) / 8;
494 size = page_align(size);
495 switch (i->type) {
496 case SND_PCM_AREA_MMAP:
497 err = munmap(i->addr, size);
498 if (err < 0) {
499 SYSERR("mmap failed");
500 return -errno;
502 errno = 0;
503 break;
504 case SND_PCM_AREA_SHM:
505 if (i->u.shm.area) {
506 snd_shm_area_destroy(i->u.shm.area);
507 i->u.shm.area = NULL;
508 if (pcm->access == SND_PCM_ACCESS_MMAP_INTERLEAVED ||
509 pcm->access == SND_PCM_ACCESS_RW_INTERLEAVED) {
510 unsigned int c1;
511 for (c1 = c + 1; c1 < pcm->channels; c1++) {
512 snd_pcm_channel_info_t *i1 = &pcm->mmap_channels[c1];
513 if (i1->u.shm.area) {
514 snd_shm_area_destroy(i1->u.shm.area);
515 i1->u.shm.area = NULL;
520 break;
521 case SND_PCM_AREA_LOCAL:
522 free(i->addr);
523 break;
524 default:
525 assert(0);
527 i->addr = NULL;
529 err = pcm->ops->munmap(pcm);
530 if (err < 0)
531 return err;
532 free(pcm->mmap_channels);
533 free(pcm->running_areas);
534 pcm->mmap_channels = NULL;
535 pcm->running_areas = NULL;
536 return 0;
539 snd_pcm_sframes_t snd_pcm_write_mmap(snd_pcm_t *pcm, snd_pcm_uframes_t offset,
540 snd_pcm_uframes_t size)
542 snd_pcm_uframes_t xfer = 0;
543 snd_pcm_sframes_t err = 0;
544 if (! size)
545 return 0;
546 while (xfer < size) {
547 snd_pcm_uframes_t frames = size - xfer;
548 snd_pcm_uframes_t cont = pcm->buffer_size - offset;
549 if (cont < frames)
550 frames = cont;
551 switch (pcm->access) {
552 case SND_PCM_ACCESS_MMAP_INTERLEAVED:
554 const snd_pcm_channel_area_t *a = snd_pcm_mmap_areas(pcm);
555 const char *buf = snd_pcm_channel_area_addr(a, offset);
556 err = _snd_pcm_writei(pcm, buf, frames);
557 if (err >= 0)
558 frames = err;
559 break;
561 case SND_PCM_ACCESS_MMAP_NONINTERLEAVED:
563 unsigned int channels = pcm->channels;
564 unsigned int c;
565 void *bufs[channels];
566 const snd_pcm_channel_area_t *areas = snd_pcm_mmap_areas(pcm);
567 for (c = 0; c < channels; ++c) {
568 const snd_pcm_channel_area_t *a = &areas[c];
569 bufs[c] = snd_pcm_channel_area_addr(a, offset);
571 err = _snd_pcm_writen(pcm, bufs, frames);
572 if (err >= 0)
573 frames = err;
574 break;
576 default:
577 SNDMSG("invalid access type %d", pcm->access);
578 return -EINVAL;
580 if (err < 0)
581 break;
582 xfer += frames;
583 offset = (offset + frames) % pcm->buffer_size;
585 if (xfer > 0)
586 return xfer;
587 return err;
590 snd_pcm_sframes_t snd_pcm_read_mmap(snd_pcm_t *pcm, snd_pcm_uframes_t offset,
591 snd_pcm_uframes_t size)
593 snd_pcm_uframes_t xfer = 0;
594 snd_pcm_sframes_t err = 0;
595 if (! size)
596 return 0;
597 while (xfer < size) {
598 snd_pcm_uframes_t frames = size - xfer;
599 snd_pcm_uframes_t cont = pcm->buffer_size - offset;
600 if (cont < frames)
601 frames = cont;
602 switch (pcm->access) {
603 case SND_PCM_ACCESS_MMAP_INTERLEAVED:
605 const snd_pcm_channel_area_t *a = snd_pcm_mmap_areas(pcm);
606 char *buf = snd_pcm_channel_area_addr(a, offset);
607 err = _snd_pcm_readi(pcm, buf, frames);
608 if (err >= 0)
609 frames = err;
610 break;
612 case SND_PCM_ACCESS_MMAP_NONINTERLEAVED:
614 snd_pcm_uframes_t channels = pcm->channels;
615 unsigned int c;
616 void *bufs[channels];
617 const snd_pcm_channel_area_t *areas = snd_pcm_mmap_areas(pcm);
618 for (c = 0; c < channels; ++c) {
619 const snd_pcm_channel_area_t *a = &areas[c];
620 bufs[c] = snd_pcm_channel_area_addr(a, offset);
622 err = _snd_pcm_readn(pcm->fast_op_arg, bufs, frames);
623 if (err >= 0)
624 frames = err;
625 break;
627 default:
628 SNDMSG("invalid access type %d", pcm->access);
629 return -EINVAL;
631 if (err < 0)
632 break;
633 xfer += frames;
634 offset = (offset + frames) % pcm->buffer_size;
636 if (xfer > 0)
637 return xfer;
638 return err;